THERE are three observations which suggest that diminution of the adenosine triphosphate (ATP) content of muscle leads to contraction: (a) the ATP and creatine phosphate (CP) content of isolated striated muscle is about 5 times that of smooth muscle1, and the latter always shows a state of partial contraction or tonus; (b) diminution of the ATP content of smooth muscle leads to contraction, and increase to relaxation2; (c) adrenaline, which causes relaxation of smooth muscle, increases the ATP content of muscle by about 70 per cent in the first 15 sec3.
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Journal of the Neurological Sciences (1970)
Archives Internationales de Physiologie et de Biochimie (1969)
Annals of the New York Academy of Sciences (1967)
Changes in contractile ability of the frog's myocardium in relation to concentration of Na, K and Ca ions in the surrounding medium
Bulletin of Experimental Biology and Medicine (1967)